1. Field of the Invention
The present invention relates to Jacquard systems for the formation of the shed on weaving machines, and more particularly to those in which the reciprocatingly to those in which the reciprocatingly moveable hooks which actuate the cords of a conventional harness are controlled by knives carried by parallel sides of a series of funicular members or belts disposed in pairs.
2. History of the Related Art
French Patent No. 2 677 380 to STAUBLI clearly illustrates the general arrangement of the systems of this type.
For driving this type of system, the movement is taken from the principal shaft of the weaving machine with the aid of a first bevel gear linked by a vertical shaft to a second bevel gear provided at the system to be driven. A horizontal output shaft of this second bevel gear constitutes an input shaft of the system, on which are generally mounted a modulator device adapted to impart to the shaft the movement desired for the system, a device for seeking the shed (unweaving) and a brake for automatically immobilizing the system as soon as the drive input has stopped.
The input shaft of the system must obviously be connected to the drums which ensure reciprocating drive of each of the knife-bearing belts, and on this point reference may be made to what was described and shown in French Patent No. 2 703 697 to STAUBLI. In this arrangement, the input shaft carries two eccentrics for controlling two vertical connecting rods which actuate two horizontal connecting rods connected to the pairs of drums. The drums have different diameters which decrease from one end of the system to the other in order to impart to the knives and to the hooks different strokes adapted to obtain an oblique shed.
It may be ascertained that such a drive mode involves a large number of different parts which increase the cost of the machine. The accessory devices (modulator, brake, shed search) increase the cost, and the connections for adjustments (stroke and obliqueness) are delicate, involving qualified manpower. Moreover, it will be noted that it is impossible to obtain non-plane yarn laps, such as those forming a so-called elliptic shed.
It is an object of the present invention to overcome these drawbacks.